James R. Mickelson

Current Position (s): Associate Professor
Veterinary PathoBiology
College of Veterinary Medicine
University of Minnesota

Research Interests and areas of potential collaboration:
Glucose and glycogen metabolism in health and disease.
Regulation of insulin sensitivity in muscle.
Insulin receptor signal transduction and the regulation of GLUT4 translocation.

Projects Underway:

Glucose transporter regulation in a novel polysaccharide storage disorder.  The heritable disorder known as polysaccharide storage myopathy in horses results in the deposition of an abnormal polysaccharide in muscle as well as muscle damage during exercise.  We have shown using hyperinsulinemic euglycemic clamping that an increased insulin sensitivity is associated with this myopathy.  We are interested in defining the precise cellular and molecular defect responsible for the altered insulin sensitivity, glucose and glycogen metabolism which we feel are likely associated with this disorder.

Selected publications:

Valberg, S.J., Townsend, D. and Mickelson, J.R.  (1998).  Skeletal muscle glycolytic capacity and phosphofructokinase regulation in horses with polysaccharide storage myopathy.  Am. J. Vet Res. 59, 782-785.

Valberg, S.J., MacLeay, J.M., Billstrom J.A., Hower-Moritz, M.A., and Mickelson, J.R. (1999). Skeletal muscle metabolic response to exercise in horses with "tying-up" due to polysaccharide storage myopathy.  Eq. Vet. J. 31, 43-47.

De La Corte, F.D., Valberg, S.J., MacLeay, J.M., Williamson, S., and Mickelson, J.R.  (1999). Glucose uptake in horses with polysaccharide storage myopathy.  Am J. Vet. Res. 60, 458-462.

De La Corte, Valberg, S.J., Mickelson, J.R., and Hower-Moritz, M. (1999).  Blood glucose clearance after exercise in polysaccharide storage myopathy. International Conference of Equine Exercise Physiology. Eq. Vet. J., Suppl 30, 324-329.